Tool-holder.



H. P. SWINBURNE & G. S. CRAWFORD.

TOOL HOLDER. APPLICATION FILED NOV. Z5| I912.

Patented July 27, 1915.

2 SHEETS-SHEET WO-Mai.

301 102 s. Kama 7% H. P. SWINBURNE & G. S. CRAWFORD.

TOOL HOLDER.

APPLICATION FILED NOV.25. 1912.

1,1%8,202. Patented July 27, 1915.

2 SHEETS-SHEET Z.

Wea- Howardlifi'wbzarne 5607565 Cmuford.

TED STATES PATENT O HOWARD r. SWINBURNE AND GEORGE s. CRAWFORD, or eL seow, SCOTL ND."

TOOL-HOLDER.

Specification of Letters Patent. Pate ntd July 27,1915.

Application filed November 25,1912. Serial No. 733,517.

T all whom it may concern .Be it known that we, HOWARD PERCY SWINBURNE and GEORGE SLoAN CRAWFORD, subjects of the King of Great Britain and Ireland, and residents of Glasgow, Scotland, engineers, have invented new and useful Improvements in Tool-Holders, of which the following is a specification.

This invention has reference to and comprises improvements in chucks or like tool holders for boring and drilling machines and the like and particularly relates to that type of chuck or tool holders which consist of a cylindrical and partly conical sleeve within which are fitted paws or wedges (usually three in number) which are tightened or pressed on to the shank of a drill or other tool by the rotation of said sleeve.

In order that our said invention and the manner of carrying the same into effect or practice may be properly. understood, we have hereunto appended three sheets of explanatory drawings in which Figure 1 is a sectional elevation of our improved chuck or tool holder for boring and drilling machines and the like. Fig. 2 is a sectional plan view taken on the line 2-2 of Fig. 1. Fig. 8 is an inverted plan view of Fig. 1. Figs. 4-, 5 and 6 are respectively an elevation, a sectional elevation and a plan View of a chuck or like tool holder as constructed according to a slightly modified arrangement of our improvements. Figs. 7 and 8 embrace elevations and plan views of details in the mechanism which will be hereinafter more particularly referred to. Figs. 9 and 10 are respectively an elevation and a sectional elevation at right angles to same of another sli htly modified construction of chuck. Fig. 11 is a sectional plan view with the driving spindle removed and taken on the line 1111 0f Fig. 10. Fig. 12 is a plan view of a detail in the mechanism which will also be hereinafter more'particularly referred to. Fig. 13 is a sectional elevation of the chuck, while Figs. ll to 17 are views of details of the construction which will also be hereinafter more particularly referred to.

Referring tothese drawings, the paws or wedges a, which are cylindrical or round in cross section and tapered at their lower ends,

are formed with recesses b and inwardly projecting flanges 0 atthelr upper ends. These paws. are fitted into recesses (1 formed in the internal surface of the partly conical cylindrical. sleeve 0 and a small ball f placed into a recess in each paw and working in a groove. 9 in the recess 0? keeps said paw in its proper position, that is, it pree vents the paw from twisting or. turning about its own longitudinal center line or axis. I

A plug 7t screwed into the upper portion of the sleeve 6 is bored for the passage of the driving spindle z and is fitted at its lower or inner end with a screwed stud or plug j formed with a notch, grooveor channel is at its upper end or face to receive the end of the spindle which is shaped to fit same. The lower end of the stud j isprovided with a head or circular flange 1 formed with a notch, grooveor channel m to receive the upper end of the tool shank n which is correspondingly shaped and this headfits into the recesses?) of the paws a whose flanges 0 bear on its upper surface.

A pinching screw 9 is preferably fitted into the plug it in order that the spindle i may be tightened in the plug it. j

It will be readily understood that asthe spindlei is rotated the toool n is positively rotated from same through the stud j by means of the projections or shaped portions on the ends of the spindle and tool shank engaging with the grooves or channels 70, m, in the stud j andas the sleeve 6 is rotated on the plug it to tighten the paws a on the tool shank n the flanges c of the paws bearing on the head ,Z of the stud j will prevent the paws from being forced longitudinally along the tool shank so that said paws will only have a movement in a direction at right angles to the longitudinal aXis of the tool shank. I I

If desired, balls 0, 22, may be fitted between the flanges c and theplugs h and in order that friction may be minimized.

As illustrated'by Figs. 41 to 8, a sleeve l (hereinafter termed the inner sleeve) is mounted on the lower or outer end 8 of the driving spindle 2' preferably between collarst and u, so that the same has practicallyno. longitudinal movement on said spindle al though it is capable of a rotary movement on same. The lower end .9 of the driving spindle 2' engages with and drives the tool hold ing means or device proper h, the upper portion '0 of which is preferably of a sleeve or socket (formation which embraces or encircles said spindle end sand which is formed at its upper end with teeth or notches to which engage with a pin 00 passed through the spindle end 8 so that when the pin 00 is in engagement with the notches w of the tool holder h and the spindle i rotated, the tool holder it will be rotated also. i

In order that the pin a: will be disengaged from the said notches to so that the tool a will not be revolved as the spindle i revolves, a pin" or projection y secured near to the upper end of the tool holder socket '12 works in an inclined slot z formed in the said inner sleeve 1 so'that if the spindle end .9 and tool holder proper h are in engagement (by means of said pin m and notches w) are being revolved and the inner sleeve 1 is held by theoperator the slot 2 in the sleeve 1 travels over the pin 3 in the socket o and raises the pin m in the spindle end .9 out of engagement with the notches w of the socket o so that the tool holder proper h is disconnected from the spindle end 8.

A sleeve 2 (hereinafter termed the outer sleeve) mounted around the inner sleeve 1 is of a tight fit to same so as to form a grip for the operator when he desires to hold the inner'sleeve'l; and if desired, these sleevesl and2 may beheld from rotating by automatic means instead of by the operator manually. This automatic means may consist of a downwardly projecting member or members 3 secured to the outer sleeve 2 and pref- 'erably adjustable as regards length, which comes intocontact with the surface 4 of the work when the drill or other tool a has reached the desired depth, thus preventing the sleeve 2 from being rotated and so disengagingthe tool holder 71. from the driving spindle 2' as hereinbefore described. These downwardly projecting members 3 may be adjustable as regards length by any suitable means, for example, their upper ends may be secured to a spring collar 5 or like device adjustable as regards its position on the outer sleeve 2, or both arrangements may be used if desired.

The aforesaid pin m on the driving spin dle end 8 and the notches w on the socket o of tool holder in may be used in conjunction with the driving plug j between the spindle end sand. the tool shank a illustrated by and described in connection with Figs. 1 to 3.

In the modification illustrated by Figs. 9 to 12 two pins y each engaging with an inclined slot 2 formed in the sleeve 1 are used instead of the one pin 7,1 and slot 2 illus- 'trated by Figs. A to 8, while the teeth or notches 'w and the pin w are dispensed with. A notch 6 is also'p'referably formed at the end of each slot zso asto permit the tool holderih to fall and be completely disengag'ed from the spindle end .9. a The outer sleeve 2 is also dispensed with and a milled or roughenedsurface 7 to form a grip for The-paws or wedges a, are cylindrical or circular in cross section and are formed at their one end with flattened portions .10 in which notches 11 are cut so that heads 12 (which correspond to the heads 0 of Fig. 1) are forme The notches or necks 11 of the paws a loosely fit slots13 formed in a disk or plate 14. mounted on the stud or plug 7' screwed into the head h of the shank, spindle or socket o of chuck. The cylindrical and partly conical sleeve 6 which screws on head it of shank o is formed with holes or orifices (one for each paw) in its conical part so that when the sleeve 6 is screwed on to head it the paws a are forced toward the longitudinal center line of the tool shank a. The plug'j is formed with a head Z between which and the head 71, the plate 14 is mounted so that when the paws a are tightened on the tool shank n the head 12 bearing on the plate 1.4 which in turn bears on the head Z, prevents said paws from having any movement along the tool shank n. A washer or disk 15 is preferably fitted between the heads 12 or paws a and the head 71, of spindle 'v. The head Z of plug j is formed with a slit or groove on into which the tongue or projection 16 formed atthe upper endof tool shank n is fitted so that positive means are provided for preventing the tool from having any rotary motion independent of the plug Theother end of plug 7', that is the screwed, end, is also formed with a groove 9 into which the tongue is formed at the end 8 of a spindle 71 passing through the shank o is fitted. When the tool is to be rotated, such as in a boring and grooves and tongues m, 9, 16 and 7c insure.

that the tool is also held rigid.

A cover or disk 17 is preferably fitted around the spindle '12 and screws into the sleeve 6.

The necks 11 of the paws afare loosely fitted into the slots 18, as before mentioned,

and since said paws are circular in cross section and are fitted into similarly shaped holes in the sleeve e when said sleeve is screwed on the head 7b, to tighten; the paws on the tool shank, said paws will be rotated loo for a small part of a revolution about their own longitudinal center line, the play or looseness between the necks 11 and the sides of the slots 18 regulating the amount of this movement. The other end of each paw a that is the opposite end from the head end, is formed tapered (Figs. 13 and 15) that is, it has a knife edge 18 which is placed along the tool shank a. When the paws are tightened on to said shank, their aforesaid small rotary movement turns the edges 18 from off the tool shank and when the tool starts to drill on the work the pressure between the cutting edge of the tool and the work causes said tool to have a tendency to rotate in a direction opposite to the partial rotation of the paws so that a looking or jamming action or effect takes place between the knife edges of the paws and the tool shank.

What we claim is 1. The combination in a chuck of a conipaws fitting the recesses of said. sleeve; and

balls in the grooves of the sleeve engaging the paws.

2. The combination in a chuck of a sleeve; paws therein; a plug engaged by said sleeve; 3. spindle connected to the plug; a stud mounted in the plug and operatively connected to the paws; and a tool shank, there being plug and recess connections between the stud, the spindle and the tool shank.

3. The combination in a chuck of a spindle; a tool holder; a socket embracing said spindle end and connected to the tool holder; a pin fitted to said socket; and a sleeve surpower from said driving spindleto the tool holder.

I 6. The combination in a chuck of an inner sleeve having a slot; an outer sleeve fitting said first sleeve; a toolholder; with a pin Copies of this patent may be'obtained for five cents each, byv addressing the Gommissioner of Patents,

secured to the tool holder and extending into said slot of the inner sleeve.

7. The combination in a chuck of a tool holder; a sleeve;'a'pin and slot connection between said sleeve and the holder; with means whereby said sleeve is automatically unclutched when a tool in the holder reaches the depth desired.

8. The combination in a chuck of a tool holder; a sleeve; a pin and slot connection between said parts; with a downwardly projecting member adjustable as regards length and secured to the sleeve, for automatioally unclutching the same when a tool in the holder reaches the depth desired.

'9. The combination in a chuck of a casing; a member therein having slots; paws having 'T-shaped heads and mounted with their necks in said slots to have a small rotary movement about their respective center lines as axes; and a tool shank to which said paws are gripped by reason of such rotary movement as caused by the action of the.

tool on'the work. w

10. The combination in a chuck of means including paws whereby a tool maybe either positively rotated or positively held from rotation; and means permitting rotation of the paws about their respective center lines to cause them to grip the tool shank by reason of the action of the tool on the work,

the same consisting of a radially slotted supporting plate slidably engaging the paws while allowing them limited rotation. 1 V

11. The combination in a chuck of a casing; a driving spindle; a stud connected to said spindle; a disk rotatably mounted on the stud and having slots; with paws or wedges formed with heads and neck parts mounted in said slots. 1

12. The combination in a chuck of a spinand paws engaged by the disk to prevent their movement longitudinally independently of the. spindle.

In testimony whereof, we have signed our names to this specificatlon, 1n the presenceof two subscribing witnesses.

H. P. swiNBURNE. e. s. CRAWFORD.

Witnesses: 1 S. C. THoMsoN, JOHN STE ART.

Washington, D. 0; 

